Distance Transform

Question

Hello everyone,
i have just signed up for the java forum and i have a problem as you may easily understand.
i have been working for a project related to image processing, and my supervisor asked me to write a code that implements one of the distance transform algorithms such as Euclidean or Gaussian. However, we do not need the transformed and grey-scale output of the input image but the coordinates and radiuses of the inner circles that represents the features of the original image.
actually i have no idea how can i compete those coordinate and radius values. so far, i have written a code that takes an image as input and then computes its pixes values (i used PixelGrabber class) in order to store them into both 1D and 2D arrays. the next step is to calculate the values of the transformed image in order to access the values i have been trying to get; however, i cannot really see any way to do so.
here is a link for those who do not have any idea about the circles i mentioned to understand what i meant:
http://sog1.me.qub.ac.uk/Research/medial/medial.php
if you have any idea about competing the circle values, i will be in your debt.
thanks to everybody who pays attention

Answer 1

here is the code i have written to obtain the pixel values.
as you can see, this code takes an image from the directory where you put the code, stores the pixel values of the input image into 1D and 2D arrays.
aside form the pixel calculation, i tried to implement a distance transform algorithm i found in the web but i think i could not correctly integrate it to my own code.
import java.awt.*;
import java.awt.image.*;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import javax.imageio.*;
    public class Pixel {
         public static void main(String[] args){
     PixelGrabber pg;
     File file;
     BufferedImage image = null;
    try {
        // Read from a file which is in the same directory with this code
        file = new File("aaa.bmp");
        image = ImageIO.read(file);
    } catch (IOException e) {
         pg = new PixelGrabber(image, 0, 0, -1, -1, false);
          try {
               System.out.println(pg.grabPixels());
          } catch (InterruptedException e) {
               e.printStackTrace();
          int ysize = image.getHeight();
          int xsize = image.getWidth();
          System.out.println("Row sizw: " + ysize + " pixel");
          System.out.println("Column Size: " + xsize + " pixel");
          pg.startGrabbing();
          byte[] data = new byte[xsize*ysize];
          data = (byte[]) pg.getPixels();
         int i=0;
          //printing the 1D array
            do{
               System.out.print(data);
          i++;
          if( i%xsize == 0)
               System.out.println();
     }while(i<data.length);
     System.out.println();
     System.out.println();
     System.out.println();*/
     //copying the 1D array to 2D array
     int index=0;
     int[][] matris = new int[ysize][xsize];
     for(int a=0; a<ysize; a++)
          for(int b=0; b<xsize; b++){
               matris[a] = data[index];
               index++;
     //printing the 2D array      
     for(int a=0; a<ysize; a++){
          for(int b=0; b<xsize; b++)
               System.out.print(matris[a][b]);
          System.out.println();
     //Backing up the 2D array      
     int[][] mat1 = new int[ysize][xsize];
     for(int a=0; a<ysize; a++)
          for(int b=0; b<xsize; b++)
               mat1[a][b] = matris[a][b];
     int temp, j;
     //performing the distance transform (got this part from net)
     for(j=0;j<ysize;j++)
          for(i=0;i<xsize;i++)
               if(mat1[i][j]==0)
                    continue;
               if((j==0)||(j==ysize-1)){
                    mat1[i][j]=1;
                    continue;
               if((i==0)||(i==xsize-1)){
                    mat1[i][j]=1;
                    continue;
     temp=findmin(mat1[i-1][j],mat1[i-1][j-1],mat1[i][j-1],mat1[i+1][j-1]);
     mat1[i][j]=temp+1;
     //performing the distance transform from bottom (got this part from net)
     for(j=ysize-1;j>=0;j--)
          for(i=xsize-1;i>=0;i--){
               if(mat1[i][j]==0)
                    continue;
               if((j==0)||(j==ysize-1)){
                    mat1[i][j]=1;
                    continue;
               if((i==0)||(i==xsize-1)){
                    mat1[i][j]=1;
                    continue;
     temp=findmin(mat1[i-1][j+1],mat1[i][j+1],mat1[i+1][j+1],mat1[i+1][j]);
     if(temp>(mat1[i][j]-1))temp=mat1[i][j]-1;
     mat1[i][j]=temp+1;
     //printing the original pixels
     for(int a=0; a<ysize; a++){
          for(int b=0; b<xsize; b++)
               System.out.print(matris[a][b]);
          System.out.println();
     System.out.println();
     System.out.println();
     System.out.println();
     //printing the transformed values
     for(int a=0; a<ysize; a++){
          for(int b=0; b<xsize; b++)
               System.out.print(mat1[a][b]);
          System.out.println();
          private static int findmin(int num1, int num2, int num3, int num4) {
               int min=4000;
               if(min>num1)
                    min=num1;
               if(min>num2)
                    min=num2;
               if(min>num3)
                    min=num3;
               if(min>num4)
                    min=num4;
               return min;
please help me about how can i convert the 2d array into an image output in order for me to check the correctness and validity of the distance transform algorithm i found in the web. and i still need to figure out how to compete the coordinates and radiuses of the circles.
thanks everybody